UPD70F3793GC-UEU-AX Datasheet, PDF (867/1113 Pages) Renesas Technology Corp – RENESAS MCU V850ES/Jx3-L Microcontrollers

V850ES/JG3-L
CHAPTER 23 STANDBY FUNCTION
Figure 23-3. Setting the RTC backup mode (1/2)
Reset start
Set RTCBUMCTL0 to 1
(specific sequence), and
RTC backup mode is enabled.
Set SOSCAMCTL.AMPHS to 0
(specific sequence), and specify
normal oscillation for the subclock (fXT).
Initial settings for
RTC backup mode
Set RTCBUMCTL0.RBMSET to 0
(specific sequence), and
exit the pre-RTC backup mode.
NOP
Initial settings for peripheral functions
Specify that the LVI be used as an interrupt.
(Use the LVIS register to set the low-
voltage detection level to 2.8 V.)^Note
Is the RTC in the initial state?
No
(RC1CC0.RC1PWR = 0?)
Yes
Initial settings for the RTC
Normal operaiton
Note The detection voltage can be set to 2.30 V (by setting the LVIS register to 01H) when
an operation clock of fXX = 2.5 to 5 MHz is used.
Remark In RTC backup mode , do not set the low-voltage detection level to 2.10 V (LVIS =
02H).
R01UH0165EJ0700 Rev.7.00
Sep 22, 2011
Page 867 of 1113